The present invention relates to a vision assist assembly for a single eye vision device and, more particularly, to such an assembly which can be (i) operatively attached to a protective head mount, such as a helmet, which is typically worn covering the forehead down to the eyes; (ii) used for selectable positioning the single eye vision device in front of the left or right eyes of the wearer by a simple sideways rotational movement in front and across the face of the wearer, thereby obviating the need for demounting the single eye vision device for such repositioning; and (iii) set aside the face when not in use, so as to minimally interfere with the naked eye field of view of the wearer.
Various types of single eye vision devices are known, some of which have specific advantages when head mounted in front of an eye of the wearer, as it leaves the hands thereof free to perform other duties. For obvious reasons, head mounted single eye vision devices, especially single eye night vision devices, are of specific importance for law enforcing agencies and armies, wherein individuals using such devices are requested to perform a plurality of other duties with their hands.
It is well recognized that while using a single eye vision device, especially such a device which produces an artificial image, e.g., a one eye night vision device, the user is, from time to time, required to change the viewing eye because continuously viewing through such an optical instrument is tiring for the eye.
U.S. Pat. No. 5,786,932 to Panel teaches a single eye vision assist device which includes a head mount, a vision assist assembly mounted on the head mount for selectable positioning in front of an eye of a wearer and a positioning apparatus for positioning the vision assist assembly on the head mount. Positioning according to Panel is effected by an apparatus capable of axial movement along an axis generally substantially orthogonal to the face of a wearer and rotational movement about the axis into and out of a position in front of the eye of the wearer. Thus, according to U.S. Pat. No. 5,786,932, the single eye vision device is rotated along the interpupillary distance between the eyes, and while at its non-use position it engages a central face position or above the eye (when a helmet is not worn).
This design has limitations because while at its non-use position the device blocks a large fraction of the naked eye field of view of the wearer. In addition, this design is at all not applicable for use with a helmet, which under field conditions, is worn down to the eyes, covering the entire forehead, for providing maximal protection.
In an attempt to overcome the above limitations, Litton Systems Inc. Electro-optical Systems Division, Tempe Operations 1215S, 52.sup.nd St., Tempe, Ariz. 85281, USA; and ITT Electrooptical Products Division 7635 Plantation Rd. Roanoke, Va. 24019, USA, have each independently developed a one eye vision device which includes a pair of dovetail or similar constructions, one for each eye, which are used for mounting the device onto a central vision assist assembly mounted on a helmet.
This design has a major limitation because in the process of repositioning the device for use by either eye, the device needs to be demounted from the vision assist assembly and remounted thereon using the other dovetail. This operation requires to remove the helmet from the head which is both cumbersome and in certain situations, dangerous.
There is thus a widely recognized need for, and it would be highly advantageous to have, a vision assist assembly devoid of the above limitations, which vision assist assembly is operatively attachable to a protective head mount, such as a helmet, which is typically worn covering the forehead down to the eyes; is used for selectable positioning the single eye vision device in front of the left or right eyes of the wearer by a simple sideways rotational movement in front and across the face of the wearer, thereby obviating the need for demounting the single eye vision device during such repositioning; and can be set aside the face of the wearer when not in use, so as to minimally interfere with the naked eye field of view of the wearer.